| Co-Investigator(Kenkyū-buntansha) |
SUGIYAMA Makoto Fac. of Agriculture, Gifu Univ. (Associate Researcher), 農学部, 助手 (80196774)
HASHIMOTO Akira Fac. of Agriculture, Gifu Univ. (Associate Professor), 農学部, 助教授 (70021706)
MINAMOTO Nobuyuki Fac. of Agriculture, Gifu Univ. (Associate Professor), 農学部, 助教授 (10144007)
HIRAI Katsuya Fac. of Agriculture, Gifu Univ. (Professor), 農学部, 教授 (30021702)
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| Research Abstract |
1. Isolation of campylobacters: A total of 2,024 fecal samples were tested for campylobacters. Isolation frequencies were 69 % in psittacine birds, 61 in pigs, 58 in chickens, 24 in pigeons, 13 in monkeys, 10 in wild rats, 10 in gunea pigs, 6 in cows, and 4 in dogs. No campylobacters were isolated from rabbits and rats. Almost all strains isolated were Campylobacter jejuni, except those from pigs, which were C. coli.
2. Prevalence of campylobacter antibody: Serum samples of 1,629 animals were tested for CF antibody against campylobacters. Positive rates were 35 % in monkeys, 19 in cows, 18 in humans, 14 in wild rats and 5 in chickens. No antibody was detected in pigs, pigeons, quail and ducks. The data seemed to indicate that campylobacters exist in chickens and pigs as microflora.
3. Antimicrobial susceptibility of campylobacters: A total of 218 strains of campylobacters were tested for susceptibilities to 6 antimicrobial drugs. Forty-one per cent of the strains were drug resistant and TC-resistance was most common. No conjugative R plasmid was detected.
4. Plasmid profiles as epidemiological markers in campylobacteriosis: Forty-two per cent (91/218) of campylobacters tested were noted to harbor plasmid DNA, ranging in size from 1.2 to 360 megadalton. The plasmid profiles were found among the strains isolated from diarrheic monkeys breeding as one group. The facts suggest that plasmid profiles are potentially useful epidemiological markers for campylobacter infection.
5. Pathogenicity of campylobacters: No plasmid specified pathogenicities such as diarrhogenicity and invasiveness into cultured cells were observed. However, if the isolates were limited to antimicrobial susceptible strains, the plasmid occurrence rate was significantly higher in the isolates from diarrheic feces than those of normal feces. More work is necessary to clarify these problem.
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